Methods for Forecasting population

                    Methods for Forecasting population


Methods for Forecasting population, Population Forecasting Methods PDF, Population Forecasting Methods PPT, Arithmetical Increase Method, Geometrical Increase Method, Incremental Increase Method, Simple Graphical Method, Population Forecasting Methods for water demand,  Population Forecasting Methods for water Supply system

Following are the methods of population forecasts or population projection :

1. Arithmetical Increase Method.

This is the most simple method of population forecast.
This method is based upon the assumption that the population is increasing at a constant rate. The rate of change of population with time is constant.i.e.

dp/dt = C ( a Constant).

The population data for the last 4 to 5 decades is obtained and the population increase per decade (x) is calculated; the average of which (X) is then used as the design growth rate for computing future population.

Thus, P1= Population after 1 decade from present
                = P0 + 1. X

P2 =  Population after 2 decade from present
     = P0 + 2X

Writing in this fashion, we get 

P(n) =  P0 + n. X

where P(n) = Future Population at the end of n decades.
P0 = Present Population
n= number of decades between now and future
X= Arithmetic mean of population increase in the known decades.

This method is not suitable for old cities or towns which have stabilized and for those large cities, which have reached their saturation point. 



2. Geometrical Increase Method.

3. Incremental Increase Method.

4. Decrease rate of growth method

5. Graphical extension method


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